(New York)--One transgender woman in Guatemala was killed and another remains in serious condition after both were shot in the head by men whom witnesses believe were police, Amnesty International said today.

"This is, sadly, only the latest in a string of murders of transgender people in Guatemala," said Dr. William F. Schulz, Executive Director of Amnesty International USA (AIUSA). "Once again, not only have police and government authorities failed to protect transgender people, but they also may be directly complicit in their deaths."

According to a local organization, there have been seven homicides of transgender sex workers in Guatemala City this year.

The incident occurred in the early hours of December 17th in Guatemala City, at the intersection of Fourth Avenue and 11th Street, when four men on motorbikes ordered two women to stop at an intersection, and then shot them. The women, Sulma (legal name Kevin Robles) and Paulina (legal name Juan Pablo Méndez Cartagena) were both transgender sex workers. Paulina was hit twice in the head; she died minutes later. Sulma was hit three times but survived, and is in serious but stable condition in a hospital. She can only speak with difficulty, as one of the bullets reportedly smashed all her front teeth.

Amnesty International is concerned that as Sulma witnessed the killing of Paulina, the attackers are likely to attempt to silence her. Authorities have not responded to requests to protect her.

Several other transgender sex workers witnessed the shooting, but are reportedly too scared to give testimony, fearing police reprisals. Police have reportedly been patrolling the streets near the shooting, in an apparent effort to intimidate the witnesses.

Since 1999 Sulma has been a member of, and worked as a volunteer for, the Guatemala City-based Organización de Apoyo a una Sexualidad Integral frente al SIDA, or Integral Sexuality AIDS Support Organization (OASIS), which works on the prevention of HIV/AIDS and provides support to Lesbian, Gay, Bisexual and Transgender (LGBT) people. Paulina had worked as a paid staff member for OASIS since 2004.

Amnesty International today mobilized its membership to contact Guatemalan authorities, calling for them to take immediate measures to protect Sulma in accordance with her own wishes, and to carry out a full, prompt and impartial investigation into the attack against Sulma and Paulina, with the results made public and those responsible brought to justice. The organization also called for authorities to take immediate measures to end the intimidation of sex workers and LGBT people, and of those working with OASIS.

"The Guatemalan authorities need to hear that they have a responsibility to protect the basic human rights of all their citizens, including their LGBT citizens, and that their lack of responsiveness will not be tolerated," said Michael Heflin, director of OUTFront, AIUSA's program on LGBT human rights.

Amnesty International said that the LGBT community in Guatemala regularly faces attacks and threats; transgender sex workers have been particularly vulnerable to attack since October 1997, when Luis Palencia (known as María Conchita), an active member of OASIS, was shot dead. Police officers are often allegedly involved in attacks, raising fears of a clandestine policy of "social cleansing" within the police force, intended to drive sex workers off the streets.